"This webpage is not available" when i upload a video

byte[] buffer;//this is the array of bytes which will hold the data (file)
   SqlConnection connection;
   protected void ButtonUpload_Click(object sender, EventArgs e)
   {
       //check the file
       if (FileUpload1.HasFile && FileUpload1.PostedFile != null && FileUpload1.PostedFile.FileName != "")
       {
           HttpPostedFile file = FileUpload1.PostedFile;//retrieve the HttpPostedFile object
           buffer = new byte[file.ContentLength];
           int bytesReaded = file.InputStream.Read(buffer, 0, FileUpload1.PostedFile.ContentLength);

           if (bytesReaded > 0)
           {
               try
               {
                   string connectionString = ConfigurationManager.ConnectionStrings["ConnString"].ConnectionString;
                   connection = new SqlConnection(connectionString);
                   SqlCommand cmd = new SqlCommand
                       ("INSERT INTO VIDEO (Video, Video_Name, Video_Size) VALUES (@video, @videoName, @videoSize)", connection);
                   cmd.Parameters.Add("@video", SqlDbType.VarBinary, buffer.Length).Value = buffer;
                   cmd.Parameters.Add("@videoName", SqlDbType.NVarChar).Value = FileUpload1.FileName;
                   cmd.Parameters.Add("@videoSize", SqlDbType.BigInt).Value = file.ContentLength;
                   using (connection)
                   {
                       connection.Open();
                       int i = cmd.ExecuteNonQuery();
                       Label1.Text = "uploaded, " + i.ToString() + " rows affected";
                   }
               }
               catch (Exception ex)
               {
                   Label1.Text = ex.Message.ToString();
               }
           }

       }
       else
       {
           Label1.Text = "Choose a valid video file";
       }
   }